ELI5: Explain Like I'm 5

David Greenglass

David Greenglass was a person who worked at a secret military facility in the United States during World War II. He was involved in a spy ring that passed secret information to the Soviet Union. Greenglass was arrested and sent to prison for revealing classified information to spies from the Soviet Union. He also had to give testimony against his brother-in-law and sister, who were involved in the same spy ring.